We owe our appreciation of the importance of soils on wine to the French winemakers, who centuries ago figured out that certain patches of ground result in far greater, more interesting wines than others.
Still, this fact wasn’t appreciated in California until recent decades. Before that, growers figured that grapevines would flourish in the same kinds of fertile, easy-to-farm flatland soils as agricultural row crops.
That was a big mistake!
It turns out that grapes do not like fertile soils, which feed the clusters too many nutrients, resulting in fat, pretty grapes that, unfortunately, are diluted in flavor. Instead (as Jess Jackson intuited), vines like the mountains, ridges, hillsides and benches of California’s rolling coastal regions, where soils are thin and nutrient-poor, and the struggle to survive makes the grapes much more concentrated and flavorful, in an almost Darwinian struggle to thrive.
These hillside vineyards also have the benefit of being well-drained; the water from rainfall runs rapidly off from them, courtesy of gravity, into the valleys and flatlands below, even in the kinds of downpours California winters can bring. This too, adds to the unusual intensity of mountain-grown wines.
Those are the generalities. Each particular swathe of vineyard land possesses its own individual characteristics, which are imparted to the wine. For example, parts of the Russian River Valley’s soils are rich in eroded minerals that used to be part of the ancient seabed, upraised after millennia of shaking from the San Andreas Fault system. Today, you’ll find minerally aromas and textures in a Chardonnay like Kendall-Jackson’s Piner Hills bottling. Then there’s K-J’s Grand Reserve Cabernet Sauvignon. About two-thirds of its grapes hail from the winery’s magnificent Alexander Mountain estate vineyards — high mountain tracts whose thin, poor soils concentrate the fruity flavors. But nearby drought-resistant trees, like madrone and Bay laurel, contribute their own intriguing notes of dried herbs and oils.
So different can patches of ground be, even when they’re pretty close in space, that differences in the resulting wines are apparent even to the casual taster. Pinot Noir is perhaps the most fascinating red wine in which to observe these nuances. The grape is said to be “transparent” because of its extreme sensitivity to where it’s grown. Two wines, made from different blocks, or sections, of the same vineyard, will show different aromas and flavors, even different degrees of hue, despite being made by the same winemaker, using identical winemaking techniques. While you can argue that these differences may be due to minute distinctions in things like slope of the hillside, orientation to the sun and direction of the vineyard rows — and these are important — it’s also a fact that tiny shifts in the composition of soil are at least as important. And, given the vast complexity of coastal California’s soils — among the most complicated in the world due to the earthquakes — it’s not surprising that one vineyard can offer so many different expressions of the same variety!
Steve Heimoff is one of America’s most respected and well-known wine writers. The former West Coast Editor for Wine Enthusiast Magazine and a contributor to Wine Spectator, he has also authored two books on the subject of California wine, including “New Classic Winemakers of California: Conversations with Steve Heimoff,” published in the fall of 2007.